Initial revision
diff --git a/progs/samples/nurb.c b/progs/samples/nurb.c
new file mode 100644
index 0000000..f90c6ee
--- /dev/null
+++ b/progs/samples/nurb.c
@@ -0,0 +1,355 @@
+/*
+ * Copyright (c) 1991, 1992, 1993 Silicon Graphics, Inc.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and
+ * its documentation for any purpose is hereby granted without fee, provided
+ * that (i) the above copyright notices and this permission notice appear in
+ * all copies of the software and related documentation, and (ii) the name of
+ * Silicon Graphics may not be used in any advertising or
+ * publicity relating to the software without the specific, prior written
+ * permission of Silicon Graphics.
+ *
+ * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF
+ * ANY KIND,
+ * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
+ * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * IN NO EVENT SHALL SILICON GRAPHICS BE LIABLE FOR
+ * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
+ * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+ * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
+ * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include <GL/glut.h>
+
+
+#ifndef CALLBACK
+#define CALLBACK
+#endif
+
+
+#define INREAL float
+
+#define S_NUMPOINTS 13
+#define S_ORDER     3   
+#define S_NUMKNOTS  (S_NUMPOINTS + S_ORDER)
+#define T_NUMPOINTS 3
+#define T_ORDER     3 
+#define T_NUMKNOTS  (T_NUMPOINTS + T_ORDER)
+#define SQRT_TWO    1.41421356237309504880
+
+
+typedef INREAL Point[4];
+
+
+GLenum doubleBuffer;
+
+GLenum expectedError;
+GLint rotX = 40, rotY = 40;
+INREAL sknots[S_NUMKNOTS] = {
+    -1.0, -1.0, -1.0, 0.0, 1.0, 2.0, 3.0, 4.0,
+    4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 9.0, 9.0
+};
+INREAL tknots[T_NUMKNOTS] = {
+    1.0, 1.0, 1.0, 2.0, 2.0, 2.0
+};
+Point ctlpoints[S_NUMPOINTS][T_NUMPOINTS] = {
+    {
+	{
+	    4.0, 2.0, 2.0, 1.0
+	},
+	{
+	    4.0, 1.6, 2.5, 1.0
+	},
+	{
+	    4.0, 2.0, 3.0, 1.0
+	}
+    },
+    {
+	{
+	    5.0, 4.0, 2.0, 1.0
+	},
+	{
+	    5.0, 4.0, 2.5, 1.0
+	},
+	{
+	    5.0, 4.0, 3.0, 1.0
+	}
+    },
+    {
+	{
+	    6.0, 5.0, 2.0, 1.0
+	},
+	{
+	    6.0, 5.0, 2.5, 1.0
+	},
+	{
+	    6.0, 5.0, 3.0, 1.0
+	}
+    },
+    {
+	{
+	    SQRT_TWO*6.0, SQRT_TWO*6.0, SQRT_TWO*2.0, SQRT_TWO
+	},
+	{
+	    SQRT_TWO*6.0, SQRT_TWO*6.0, SQRT_TWO*2.5, SQRT_TWO
+	},
+	{
+	    SQRT_TWO*6.0, SQRT_TWO*6.0, SQRT_TWO*3.0, SQRT_TWO
+	}  
+    },
+    {
+	{
+	    5.2, 6.7, 2.0, 1.0
+	},
+	{
+	    5.2, 6.7, 2.5, 1.0
+	},
+	{
+	    5.2, 6.7, 3.0, 1.0
+	}
+    },
+    {
+	{
+	    SQRT_TWO*4.0, SQRT_TWO*6.0, SQRT_TWO*2.0, SQRT_TWO
+	},
+	{
+	    SQRT_TWO*4.0, SQRT_TWO*6.0, SQRT_TWO*2.5, SQRT_TWO
+	}, 
+	{
+	    SQRT_TWO*4.0, SQRT_TWO*6.0, SQRT_TWO*3.0, SQRT_TWO
+	}  
+    }, 
+    {
+	{
+	    4.0, 5.2, 2.0, 1.0
+	},
+	{
+	    4.0, 4.6, 2.5, 1.0
+	},
+	{
+	    4.0, 5.2, 3.0, 1.0
+	}  
+    },
+    {
+	{
+	    SQRT_TWO*4.0, SQRT_TWO*6.0, SQRT_TWO*2.0, SQRT_TWO
+	},
+	{
+	    SQRT_TWO*4.0, SQRT_TWO*6.0, SQRT_TWO*2.5, SQRT_TWO
+	},
+	{
+	    SQRT_TWO*4.0, SQRT_TWO*6.0, SQRT_TWO*3.0, SQRT_TWO
+	}  
+    },
+    {
+	{
+	    2.8, 6.7, 2.0, 1.0
+	},
+	{
+	    2.8, 6.7, 2.5, 1.0
+	},
+	{
+	    2.8, 6.7, 3.0, 1.0
+	}   
+    },
+    {
+	{
+	    SQRT_TWO*2.0, SQRT_TWO*6.0, SQRT_TWO*2.0, SQRT_TWO
+	},
+	{
+	    SQRT_TWO*2.0, SQRT_TWO*6.0, SQRT_TWO*2.5, SQRT_TWO
+	},
+	{
+	    SQRT_TWO*2.0, SQRT_TWO*6.0, SQRT_TWO*3.0, SQRT_TWO
+	}  
+    },
+    {
+	{
+	    2.0, 5.0, 2.0, 1.0
+	},
+	{
+	    2.0, 5.0, 2.5, 1.0
+	},
+	{
+	    2.0, 5.0, 3.0, 1.0
+	} 
+    },
+    {
+	{
+	    3.0, 4.0, 2.0, 1.0
+	},
+	{
+	    3.0, 4.0, 2.5, 1.0
+	},
+	{
+	    3.0, 4.0, 3.0, 1.0
+	} 
+    },
+    {
+	{
+	    4.0, 2.0, 2.0, 1.0
+	},
+	{
+	    4.0, 1.6, 2.5, 1.0
+	},
+	{
+	    4.0, 2.0, 3.0, 1.0
+	}    
+    }
+};
+GLUnurbsObj *theNurbs;
+
+
+static void CALLBACK ErrorCallback(GLenum which)
+{
+
+    if (which != expectedError) {
+	fprintf(stderr, "Unexpected error occured (%d):\n", which);
+	fprintf(stderr, "    %s\n", (char *) gluErrorString(which));
+    }
+}
+
+static void Init(void)
+{
+
+    theNurbs = gluNewNurbsRenderer();
+    gluNurbsCallback(theNurbs, GLU_ERROR, ErrorCallback);
+
+    gluNurbsProperty(theNurbs, GLU_SAMPLING_TOLERANCE, 15.0);
+    gluNurbsProperty(theNurbs, GLU_DISPLAY_MODE, GLU_OUTLINE_PATCH);
+
+    expectedError = GLU_INVALID_ENUM;
+    gluNurbsProperty(theNurbs, ~0, 15.0);
+    expectedError = GLU_NURBS_ERROR13;
+    gluEndSurface(theNurbs);
+    expectedError = 0;
+
+    glColor3f(1.0, 1.0, 1.0);
+}
+
+static void Reshape(int width, int height)
+{
+
+    glViewport(0, 0, (GLint)width, (GLint)height);
+
+    glMatrixMode(GL_PROJECTION);
+    glLoadIdentity();
+    glFrustum(-2.0, 2.0, -2.0, 2.0, 0.8, 10.0);
+    gluLookAt(7.0, 4.5, 4.0, 4.5, 4.5, 2.5, 6.0, -3.0, 2.0);
+    glMatrixMode(GL_MODELVIEW);
+}
+
+static void Key2(int key, int x, int y)
+{
+
+    switch (key) {
+      case GLUT_KEY_DOWN:
+	rotX -= 5;
+	break;
+      case GLUT_KEY_UP:
+	rotX += 5;
+	break;
+      case GLUT_KEY_LEFT:
+	rotY -= 5;
+	break;
+      case GLUT_KEY_RIGHT:
+	rotY += 5;
+	break;
+      default:
+	return;
+    }
+
+    glutPostRedisplay();
+}
+
+static void Key(unsigned char key, int x, int y)
+{
+
+    switch (key) {
+      case 27:
+	exit(1);
+    }
+}
+
+static void Draw(void)
+{
+
+    glClear(GL_COLOR_BUFFER_BIT);
+
+    glPushMatrix();
+
+    glTranslatef(4.0, 4.5, 2.5);
+    glRotatef(rotY, 1, 0, 0);
+    glRotatef(rotX, 0, 1, 0);
+    glTranslatef(-4.0, -4.5, -2.5);
+
+    gluBeginSurface(theNurbs);
+    gluNurbsSurface(theNurbs, S_NUMKNOTS, sknots, T_NUMKNOTS, tknots,
+		    4*T_NUMPOINTS, 4, &ctlpoints[0][0][0], S_ORDER,
+		    T_ORDER, GL_MAP2_VERTEX_4);
+    gluEndSurface(theNurbs);
+
+    glPopMatrix();
+
+    glFlush();
+
+    if (doubleBuffer) {
+	glutSwapBuffers();
+    }
+}
+
+static GLenum Args(int argc, char **argv)
+{
+    GLint i;
+
+    doubleBuffer = GL_FALSE;
+
+    for (i = 1; i < argc; i++) {
+	if (strcmp(argv[i], "-sb") == 0) {
+	    doubleBuffer = GL_FALSE;
+	} else if (strcmp(argv[i], "-db") == 0) {
+	    doubleBuffer = GL_TRUE;
+	} else {
+	    printf("%s (Bad option).\n", argv[i]);
+	    return GL_FALSE;
+	}
+    }
+    return GL_TRUE;
+}
+
+int main(int argc, char **argv)
+{
+    GLenum type;
+
+    glutInit(&argc, argv);
+
+    if (Args(argc, argv) == GL_FALSE) {
+	exit(1);
+    }
+
+    glutInitWindowPosition(0, 0); glutInitWindowSize( 300, 300);
+
+    type = GLUT_RGB;
+    type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
+    glutInitDisplayMode(type);
+
+    if (glutCreateWindow("NURBS Test") == GL_FALSE) {
+	exit(1);
+    }
+
+    Init();
+
+    glutReshapeFunc(Reshape);
+    glutKeyboardFunc(Key);
+    glutSpecialFunc(Key2);
+    glutDisplayFunc(Draw);
+    glutMainLoop();
+	return 0;
+}